Initiators for cationic polymerization

ABSTRACT

Disclosed are novel compounds which are useful as initiators for cationically polymerizable monomers. The novel compounds comprise a carbon containing cation (e.g., trimethyloxonium) which is capable of initiating cationic polymerization and a non-nucleophilic counterion which is an at least partially fluorinated hydrocarbylsulfonato metallate (e.g. perfluoroethylsulfonato-aluminate). The disclosed initiators are capable of initiating the cationic polymerization of a wide variety of monomers such as epoxides, tetrahydrofuans, oxazolines, vinyls, lactones, and the like.

This is a division of application filed Feb. 12, 1990 now U.S. Pat. No.5,084,586.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to novel salt compounds containing onium cationsand non-nucleophilic complex metallate anions and more particularly, itrelates to anions with at least partially fluorinated ligand coordinatedto the metal. It also relates to the use of the compounds as novelinitiators for the cationic polymerization of various monomers.

2. Background of the Art

Iodonium, oxonium, sulfonium, sulfoxonium, and various other onium saltsare well known in the art, particularly as initiators of cationic andfree radical polymerization. The effectiveness of these onium salts asinitiators in cationic polymerizations, and particularly in achievinghigh molecular weight polymers, is known to be greatly influenced by thenucleophilic nature of the anion employed in the salt. Generally,non-nucleophilic anions function much better than their nucleophiliccounterparts. This is because strong nucleophilic anions have a muchgreater tendency to terminate the polymer chain than do non-nucleophilicanions.

Examples of nucleophilic anions which are recognized as beingdetrimental counterions include fluoride, chloride, bromide, iodide,bisulfide, cyanide, bicarbonate, carbonate, nitrate, hydroxide,carboxylates, sulfonates, and trifluoromethanesulfonate (also referredto commonly as "triflate").

Examples of non-nucleophilic anions include hexafluorophosphate (1-),hexafluoroarsenate (1-), tetrafluoroborate (1-), hexafluoroantimonate(1-), tetraphenylborate (1-), and perchlorate. The use of suchnon-nucleophilic ions as counterions for nucleophilic sensitive cationsis known, e.g., triethyloxonium tetrafluoroborate is a known stablecomplex. (see Meerwein, H. Org. Syn. Coll. Vol. V, 1080, 1096.

Triflate species, when paired with various materials, have been used ascounterions. For example, the trifluoromethanesulfonate substituted tincentered anion is known as a counterion in organometallic complexesinvolving the +4 oxidation state of tin (see Mallela, et al., Can. J.Chem. 1987, 65, 2649). By further way of example,tetrakis(trifluoromethanesulfonato)iodate (1-) anion has been preparedas salts with alkali metals (see Dalziel, J. R.; Aubke, F., Inorg. Chem.1973, 12, 2707) and tetrakis(trifluoromethanesulfonato)boric acid isknown in the art for use in Friedel-Crafts alkylations (see Miethchen,R. et al., Z. Chem. 1986, 26, 168).

U.S. Pat. No. 4,721,559 discloses the use of boron, aluminum, andgallium perfluoroalkane sulfonates as Friedel-Crafts catalysts.

U.S. Pat. No. 4,547,474 discloses the use of C₁₀ to C₁₈ perfluorinatedalkanesulfonic acid based superacidic catalysts in various hydrocarbonconversion processes.

U.S. Pat. No. 4,472,268 discloses a process for upgrading naturalgasoline by treatment with a liquid ternary catalyst system comprisingtrifluoromethanesulfonic acid and hydrogen fluoride in conjunction witha Lewis Acid catalyst of the formula MX_(n) where M is selected fromGroups IIIA, IVB, or V elements of the Periodic Table, X is halogen, andn is a number varying from 3 to 6.

SUMMARY OF THE INVENTION

The present invention provides an effective initiator for the cationicpolymerization of a wide variety of cationically polymerizable monomers.Also provided is a process using the initiators of this invention incationic polymerization reactions.

Briefly, the inventive initiator comprises an onium cation which iseffective in the cationic polymerization of various monomers and anon-nucleophilic anion which does not interfere with cationicpolymerizaton reactions. The inventive initiator comprises a compoundwhich may be represented by the following formula:

    Y.sub.a.sup.b+ [(RSO.sub.3).sub.n M)].sup.z-

wherein:

Y is a cation selected from the group consisting of oxonium, sulfonium,sulfoxonium, selenonium, iodonium, diazonium, pyrylium, carbenium, andacylium cations;

R is independently selected from the group consisting of: ##STR1## R₁ ishydrogen, halogen, an alkyl group or an aryl group; F is fluorine;

M is an element chosen from Groups 3-15, inclusive, of the Periodictable; z is 1, 2, 3, or 4; and a, b, and n are integers with the provisoz≦n and that integer a multiplied by integer b equals z.

The novel polymerization process of the present invention comprisesintimately contacting a cationically polymerizable monomer with acationic polymerization initiator of the formula

    Y.sub.a.sup.b+ [(RSO.sub.3).sub.n M)].sup.z-

as defined above, thereby initiating polymerization of said monomer.Preferably, the intimate contacting is done in solution. Generally, themere intimate contacting of the initiator and monomer will be sufficientto effect initiation of cationic polymerization. However, it will bepreferable in some cases, depending upon the type of initiator, to helpinduce initiation or accelerate the reaction through the use of heat oractinic radiation.

COMPARISON TO THE PRIOR ART

Various types of perfluorosulfonato-containing compounds are known inthe prior art and have been used as counterion ions with simple cations,e.g., potassium iodine tetrakis(trifluoromethanesulfonate)iodate (1-)(see Dalziel, J. R.; Aubke, F. Inorg. Chem. 1973, 12, 2707). Theinitiators of the present invention differ because the cationic speciesis an alkyl or aryl substituted non-metallic cation and not an alkalimetal like potassium and additionally, iodine is not within the scope ofanion of the present invention. The foregoing reference also makes nomention of using the potassium salt of iodine triflate in hydrocarbonconversion reactions.

S. R. Mallela et al. disclosed the existence of a series ofhetero-bimetallic fluorosulfonate bridged coordination polymers of thetype M(II)Sn(SO₃ F)₆ wherein M(II)=Mn, Fe, Co, Ni, or Cu (see Mallela,S. P. et al., Can. J. Chem. 1987, 65, 2649). The present inventiondiffers from this reference because the cation in the present inventionis alkyl- or aryl-substituted and the anion contains alkyl or arylgroups, the presence of which in the anion help to prevent thetermination of the polymer chain by a strong nucleophile such asfluorine. No disclosure is given by the reference for use of thedisclosed coordination polymer in any hydrocarbon conversion reactionssuch as cationic polymerizaton.

The perfluoroalkanesulfonates of boron, aluminum, and gallium, disclosedin U.S. Pat. No. 4,721,559 are all charge neutral species unlike thenegatively charged anionic species of the present invention.

The perfluorinated alkanesulfonic acids disclosed in U.S. Pat. No.4,547,474 are conventional protic acids containing an anion with nometallic substance. Furthermore, the sulfonic acids are all absorbed onsupports, such as silica, to which Lewis acids are bonded. The presentinvention does not require supports to absorb the cation and anion ofthe initiator.

Unlike the prior art, the present invention pertains to certain alkyl oraryl substituted onium cations in combination with at least partiallyfluorinated alkanesulfanatometallate counterions. A particularlyeffective cationic polymerization initiator is achieved because theonium cations are all effective initiators of cationic polymerizationand the at least partially fluorinated counterions employed are allnon-nucleophilic and therefore serve to terminate the polymerizationreaction less than conventional, prior art polymerization terminatorsdo. Consequently, as will be seen by the examples later herein, theinventive polymerization initiators help produce higher molecular weightpolymers.

DETAILED DESCRIPTION OF THE INVENTION

The novel cationic polymerization initiators of the present inventionmay be represented by the formula:

    Y.sub.a.sup.b+ [(RSO.sub.3).sub.n M)].sup.z-

wherein: Y is a cation selected from the group consisting of oxonium,sulfonium, sulfoxonium, selenonium, iodonium, diazonium, pyrylium,carbenium, and acylium cations.

Non-limiting examples of these cations include, but are not limited to:trialkyloxonium, preferably trialkyloxonium having from 3 to 54 carbonatoms (e.g., trimethyloxonium, triethyloxonium, trihexyloxonium,trioctadecyloxonium, etc.); alkyldiaryloxonium, preferablyalkyldiaryloxonium having from 8 to 60 carbon atoms (e.g.,dimethylphenyloxonium, octylmethylnaphthyloxonium, etc.);aryldialkyloxonium, preferably aryldialkyloxonium having from 14 to 48carbon atoms; triaryloxonium, preferably triaryloxonium having from 18to 45 carbon atoms (e.g., triphenyloxonium, diphenyl(naphthyl)oxonium,etc.); trialkylsufonium, preferably trialkylsufonium having from 3 to 54carbon atoms (e.g., trimethylsulfonium, tributylsufonium,dimethylethylsulfonium, etc.); alkyldiarysulfonium, preferablyalkyldiarylsulfonium having from 8 to 60 carbon atoms (e.g.,diphenylmethylsulfonium, ethylphenylnaphthylsulfonium, etc.);aryldialkylsulfonium, preferably aryldialkylsufonium having from 14 to48 carbon atoms (e.g., diethylphenylsulfonium,ethyloctadecylphenylsulfonium, etc.); triarylsulfonium, preferablytriarylsulfonium having from 18 to 45 carbon atoms (e.g.,triphenysulfonium, diphenylnaphthylsulfonium, etc.); trialkylsufoxonium,preferably trialkylsulfoxonium having from 3 to 54 carbon atoms (e.g.,trimethylsulfoxonium, tributylsulfoxonium, dimethylethylsulfoxonium,etc.); alkyldiarylsulfoxonium, preferably alkyldiarylsulfoxonium havingfrom 8 to 60 carbon atoms (e.g., diphenylmethylsulfoxonium,ethylphenylnaphthylsulfoxonium, etc.); aryldialkylsulfoxonium,preferably aryldialkylsulfoxonium having from 14 to 48 carbon atoms(e.g., diethylphenylsulfoxonium, ethyloctadecylphenylsulfoxonium, etc.);triarylsulfoxonium, preferably triarylsulfoxonium having from 18 to 45carbon atoms (e.g., triphenylsulfonium, diphenylnaphthylsulfonium,etc.); trialkylselenoium, preferably trialkylselenonium having from 3 to54 carbon atoms (e.g., trimethylselenonium, triethylselenonium,trihexylselenonium, trioctadecylselenonium, etc.); alkyldiaryselenonium,preferably alkyldiarylselenonium having from 8 to 60 carbon atoms (e.g.,dimethylphenylselenoium, octylmethylnaphthylselenonium, etc.);aryldialkylselenonium, preferably aryldialkylselenonium having from 14to 48 carbon atoms (e.g., triarylselenonium, preferablytriarylselenonium having from 18 to 45 carbon atoms (e.g.,triphenylselenonium, diphenyl(naphthyl)selenonium, etc.);dialkyliodonium, preferably dialkyliodonium having from 2 to 36 carbonatoms (e.g., dimethyliodonium, hexylpropyliodonium, diocatdecylodonium,etc.); alkylaryliodonium, preferably alkylaryliodonium having from 7 to35 carbon atoms (e.g., methylphenyliodonium, ethylphenyliodonium, etc.);alkynylaryliodonium, preferably alkynylaryliodonium having from 8 to 33carbon atoms (e.g., phenyl(phenylethynyl)iodonium,naphthyl(phenylethynyl)iodonium, etc.); diaryliodonium, preferablydiaryliodonium having 12 to 30 carbon atoms (e.g., diphenyliodonium,naphthylphenyliodonium, etc.); alkyldiazonium, preferably alkyldiazoniumhaving from 1 to 18 carbon atoms (e.g., methyldiazonium, hexyldiazonium,etc.); aryldiazonium, preferably aryldiazonium having from 6 to 15carbon atoms(e.g., phenyldiazonium, naphthyldiazonium, etc.);alkylacylium, preferably alkylacylium having from 2 to 19 carbon atoms(e.g., acetylium, butylium, decylium, etc.); arylacylium, preferablyarylacylium having from 7 to 16 carbon atoms (e.g., benzoylium,naphtoylium, etc.); triarylcarbenium such as triphenylcarbenium (i.e.,trityl), etc; and pyrylium, preferably pyrylium having from 5 to 50carbon atoms. The substituents on the oxonium, sulfonium, sulfoxonium,and iodonium cations may either be individually distinct or be connectedto each other so as to form one or more rings, including aromatic rings,containing the heteroatom O, S, or I.

The onium cations employed in the present invention are prepared bythose methods which are well known to those skilled in the art.Typically in the same reaction that the onium cation is formed, ananionic (counterion) species will also be formed and thus an onium saltis created in the overall process. For example, trialkyloxonium saltswith perhalogenated complex anions are generally prepared by alkylationof dialkyl ethers using alkyl halides as alkylating agents in thepresence of strong halide acceptors such as halogenated Lewis acids(Perst, H. Carbonium Ions; Olah, G. A.; Schleyer, P. v. R., Eds.; JohnWiley & Sons, New York, 1976 1961-2047). Additionally, oxonium salts mayalso be prepared by using perfluoroalkanesulfonated Lewis acid-etheradducts in the presence of epichlorohydrin via the intermediacy of aninner oxonium salt similar to procedures known in the art to incorporatethe perfluorinated anions in the oxonium salts (see Meerwein, H.;Battenberg, E.; Gold, H.; Pfeil, E.; William, G. J. Prakt. Chem. 1939,154, 83; Meerwein, H.; Hinz, G.; Hoffman, P.; Kronig, E.; Pfril, E. J.Prakt. Chem., 1937, 147, 257; and Meerwein, H. Org. Synth. 1966, 46,113).

Trialkyloxonium salts of the present invention may also be prepared byusing secondary oxonium ion salts with a per(perfluoroalkanesulfonated)complex anion using diazo alkanes similar to the procedure known in theart for the preparation of certain perfluorinated oxonium salts (seeKlages, F.; Meuresch, H. Chem. Ber. 1952, 85, 863; and Klages, F.;Meuresch, H.; Steppich, W. Ann. Chem. Liebigs. 1955, 592, 116).Furthermore, disproportionation of the perfluoroalkanesulfonated strongLewis acid-ether adducts also gives oxonium salts similar to thosedescribed herein (see Goodrich, R. A.; Treichel, P. M. J. Am. Chem. Soc.1966, 88, 3509). Oxonium salts of the present invention are alsoprepared using trans-alkylation reactions. Thus, trimethyloxoniumtetrakis(trifluoromethanesulfonato)aluminate was prepared usingtriethyloxonium tetrakis(trifluoromethanesulfonato)aluminate in dimethylether in respectable yield.

Diaryliodonium salts of the present invention can be prepared by theaction of diaryliodonium perfluoroalkanesulfonates on appropriateperfluoroalkanated Lewis acids (e.g., diaryliodoniumtetrakis(trifluoromethanesulfonato)borate(131 )), or by the action ofdiaryliodonium perfluoroalkanesulfonates on appropriate halogenatedlewis acids followed by removal of halides using required amounts ofperfluoroalkanesulfonic acid. In lieu of diaryliodoniumperfluoroalkanesulfonates, the corresponding halides or pseudohalidescan be employed with perfluoroalkanesulfoated or halogenated Lewis acidsfollowed by a stoichiometric amount of perfluoroalkanesulfonic acid.Diaryliodnium salts of the present invention are also convenientlyprepared using the corresponding halides with appropriate metal salts ofa per(perfluoroalkanesulfonated) complex anion (e.g., coinage and alkalimetal salts as exemplified by the preparation of diphenliodoniumtetrakis(trifluoromethanesulfonato)borate(1-) using silvertetrakis(trifluoromethanesulfonato)borate(1-)). This procedure issimilar to those known in the art viz. use of alkali metal salts withperfluorinated anions (see Crivello, J. V.; Lam, H. W. J. Polym. Sci.Symp. 1976, 36, 383; and U.S. Pat. Nos. 4,151,175; 4,238,394; 4,683,317;4,529,490 to Crivello). Metal salts of per(perfluoroalkanesulfonated)complex anions used in the preparation of said iodonium salts mayconveniently be replaced by conjugate Bronsted Lewis superacids havingsame type of complex anion similar to procedures known in the art(Pappas, S. P.; Pappas, B. C.; Gatechair, L. R. J. Polym. Sci., Polym.Chem. Ed. 1984, 22, 69).

The procedures outlined for the preparation of diaryliodonium salts mayequally be applied to that of triarylsulfonium salts of the presentinvention. The sulfonium salts, however, may also be prepared by theaction of a diaryliodonium salt/per(perfluoroalkanesulfonated) complexanion on a diarysulfide using a copper salt as catalyst (see Crivello,J. V.; Lam, H. W. J. Polym. Sci., Polym. Chem. Ed. 1979, 17, 977.

The non-nucleophilic anion of the cationic polymerizaton initiator ofthe present invention is described by the formula:

    [(RSO.sub.3).sub.n M].sup.z-

and serves as a counterion to the cationic species Y_(a) ^(b+).

In the foregoing formula each R is independently selected from the groupconsisting of: ##STR2## wherein R₁ represents either hydrogen, halogen,an alkyl group or an aryl group and F is fluorine. Preferably, each Rwill individually represent a perfluorinated alkyl radical or aperfluorinated aryl radical and most preferably, a C₁ -C₁₀perfluorinated alkyl radical.

M is an element chosen from Groups 3-15, inclusive, of the PeriodicTable as depicted in Chemical and Engineering News 1985, 63, 26.Preferably M is an element chosen from Groups 4-14 of the PeriodicTable, and more preferably is chosen from the group of B, Al, Ga, Sn,Fe, Zr, Hf, Nb, and Ta.

In the foregoing formula, z is 1, 2, 3, or 4 and a, b, and n areintegers such that z is less than or equal to n and the product ofinteger a multiplied by integer b equals z.

As is well understood in this technical area, a large degree ofsubstitution is not only tolerated, but is often advisable. As a meansof simplifying the discussion and recitation of these groups, the terms"group" and "radical" are used to differentiate between chemical speciesthat allow for substitution or which may be substituted. For example,the phrase "alkyl group" is intended to include not only purehydrocarbon alkyl chains such as methyl, ethyl, octyl, cyclohexyl,isoctyl, tert-butyl and the like, but also such alkyl chains bearingsuch conventional substituents in the art such as hydroxyl, alkoxy,phenyl, halo (F, Cl, Br, I), cyano, nitro, amino, etc. The phrase "alkylradical" on the other hand is limited to the inclusion of only purehydrocarbon alkyl chains such as methyl, ethyl, propyl, cyclohexyl,isooctyl, tert-butyl, and the like.

Although the anion of the present invention can be formed in the samereaction with the onium cation thereby creating onium salt as describedearlier herein, there may be instances, as will be seen by the Examples,where it is appropriate to synthesize the anionic species separately andthen combine it with an onium cation that has been separated from anonium salt.

Thus, perfluoroalkanesulfonated complex anions of the present inventioncan themselves be prepared by one or more of the following generalprocedures:

(1) Reaction of a perfluoroalkanesulfonated strong Lewis acid with aperfluoroalkanesulfonated precursor. Suitable precursors include, butare not limited to, alkali metal and alkaline earth metalperfluoroalkanesulfonates; ammonium and phosphonium, including alkyl andaryl substituted ammonium and phosphonium, perfluoroalkanesulfonates;alkyl perfluoroalkanesulfonates; pyridinium and substituted pyridiniumperfluoroalkanesulfonates.

(2) Removal of halides (e.g., F-, Cl-, Br-, I-) or pseudo-halides (i.e.,strongly electron withdrawing groups such as cyano, nitrosyl,thiocyanato, and the like) from a perhalogenated orper(pseudo-halogenated) or mixed halogenated-perfluoroalkanesulfonatedcomplex anion by stoichiometric amounts of perfluoroalkanesulfonic acidsat sub-zero or higher temperature depending on the reactivity of theanion toward acids used. Removal of halide from the correspondingcomplex anion may also be effected by using coinage or alkali metalperfluoroalkanesulfonates (e.g., silver triflate) to cause theprecipitation of metal halides.

(3) Removal of alkyls, aryls, halides or pseudo-halides from aperalkylated, perarylated, peralkarylated, mixed alkyl-halogenated,mixed aryl-halogenated or mixed pseudo-halogenated complex anion byusing appropriate equivalents of perfluoroalkanesulfonic acid underconditions mentioned in (2). Because formation of alkanes or arenes bythe action of acid is a highly favorable irreversible thermodynamicprocess, it may result in ready preparation of the complex anions ofpresent invention. Many metal alkyls are extremely reactive even to weakacids (e.g., alcohols (see Mole, T.; Jeffery, E. A. OrganoaluminumCompounds; Elsevier: New York, 1972); Giannini, U.; Zucchini, U.:Albizzati, E.; D'Angelo, R. Chem. Comm., 1969, 1174; Giannini, U.;Zucchini, U, Chem. Co, 1968, 940; Pedley, J. B.; Marshal, E. M. J. Phys.Chem. Ref. Data. 1984, 12, 967; Smoes, S.; Myers, C. E.; Drowart J.Chem. Phys. Lett. 1971, 8, 10; Gupta, S. K.; Gingerich, K. A. J. Chem.Phys. 1981, 74, 3584; Stearns, C. A.; Kohl, F. J. High Temp. Sci. 1974,6, 284).

Suitable monomers for polymerization by the initiators of the presentinvention are those which can be polymerized cationically throughinitiation by an alkyl, or aryl containing cation; examples include, butare not limited to, cyclic ethers such as epoxides (e.g., styrene oxide,vinylcycohexene dioxide, glycidylmethactylate, ethylene oxide,epichlorohydrin, etc.), oxetanes (e.g., oxetane, phenyloxetane, etc.),tetrahydrofurans (e.g., tetrahydrofuran, 2-methyltetrahydrofuran, etc.),tetrahydropyrans (tetrahydropyran, 3-propyltetrahydropyran, etc.), etc.;alkenyl monomers such as styrene and its homologs, alkenylfurans,conjugated dienes (e.g., cyclopentadiene, 2,4-hexadiene, etc.),isobutylene, vinyl ethers (e.g., methyl vinyl ether, ethyl vinyl either,octadecyl vinyl ether, phenyl vinyl ether, etc.) including fluorinatedvinyl ethers; lactones (e.g., β-propiolactone, γ-butyrolactone,δ-caprolactone, etc.); oxazolines (e.g., oxazoline, 2-phenyloxazoline,2-decyloxazoline, etc.); aziridines (e.g., aziridine, N-ethylaziridine,etc.); cyclosiloxanes (e.g., hexamethyltrisloxanes,octamethylcyclotetrasiloxane, triphenyltrimethylcyclotrisiloxane, etc.);ketals (e.g., 1,3-dioxolane, 1,3-dioxane, 2,2-dimethyl-1,3-dioxane,2-phenyl-1,3-dioxane, 2,2-dioxolane-1,3-dioxolane, etc.); cyclicanhydrides (e.g., phthalic anhydride, maleic anhydride, succinicanhydride, etc.); lactams (e.g., β-propiolactam, γ-butyrolactam,δ-caprolactam, etc.); and aryl dialdehydes (e.g.,1,2-benzenedicarboxaldehyde, 1,3-benzenedicarboxaldheyde,1,2-naphthalenedialdehyde, etc.).

The monomer and cationic polymerization initiator should be brought intointimate contact with one another in order to initiate polymerization.As used herein, "intimate contact" between the initiator and the monomeroccurs when the two are brought into such direct or close physicalcontact that one or more cationic groups which initiate polymerizationare transferred from the initiator to the monomer. Typically this isdone in solution. In some instances, depending upon the type of cationicinitiator used, it will be preferable to use heat or actinic radiationto induce initiation of polymerization or increase its rate. Theauxiliary conditions used in conjunction with certain cations is wellknown in the art, such as, for example, the use of heat in conjunctionwith oxonium cations and the use of actinic radiation and aphotosensitizer in conjunction with iodonium cations.

Conditions for cationic polymerization of monomers is well known in theart. For example, it is desirable to have essentially anhydrous solutionconditions. It is also desirable to have high purity monomers. In orderto effect many cationic polymerizations, it is necessary to supply asource of heat. In the case of photoinitiators, it is necessary toexpose the photoinitiator to actinic radiation.

The following non-limiting examples further illustrate the presentinvention.

EXAMPLES

The materials prepared in the following examples were analyzed by one ormore of the following techniques and gave results consistent with theassigned identities: ¹ H, ²⁷ Al, ¹³ C, ¹¹ B nuclear magnetic resonance,melting point, elemental analysis, mass spectroscopy, infraredspectroscopy, and in the case of polymers gel permeation chromatography.

All materials were obtained from Aldrich Chemical Company (Milwaukee,Wis.) unless otherwise indicated.

EXAMPLE 1

This example describes the preparation of triethyloxoniumtetrakis(trifluoromethanesulfonato)aluminate (1-).

To a well stirred slurry of 4.2 g (8.86 mmol) aluminumtrifluoromethanesulfonate in 40 ml dry ether in a Schlenk flask underdry argon was added 4.6 ml (36 mmol) ethyl trifluoromethanesulfonate.The mixture was refluxed for about 20 hr during which a beigeprecipitate formed. The supernatant solution was removed and fresh etherwas added to restore the original volume, and the mixture was refluxedunder argon an additional hour. The procedure was repeated 4 times andfinally the ether was removed and the beige solid dried in vacuo at5°-100° C. for 2 hours to isolate the oxonium salt, 5.6 g (88% yield).

EXAMPLE 2

This example describes the preparation of triethyloxoniumtetrakis(trifluoromethanesulfonateo)gallate (1-).

The procedure of example 1 was followed using 4.59 g galliumtrifluoromethanesulfonate in place of the aluminumtrifluoromethansulfonate. The oxonium salt, 5.5 g was obtained (81%yield).

EXAMPLE 3

This example describes the preparation of trimethyloxoniumtetrakis(trifluoromethanesulfonate)aluminate (1-).

In a dry box 2.1 g (4.43 mmol) aluminum trifluoromethanesulfonate and 2ml (18 mmol) methyl trifluoromethanesulfonate were added to 30 ml dry1,1,2-trichlorotrifluoroethane in an autoclave equipped with a magneticstirrer. About 30 g dimethyl ether was condensed into the autoclave byapplication of a low temperature bath. After sealing the autoclave washeated to 40° C. for 8-12 hr. The autoclave was cooled to roomtemperature and slowly discharged. The beige solid was transferred to aSchlenk flask in the dry box and washed several times with dry1,1,2-trichlorotrifluoroethane and finally dried in vacuo at 50° C. for2 hr, 2.6 g (90% yield).

EXAMPLE 4

This example describes the preparation of trimethyloxoniumtetrakis(trifluoromethanesulfonato)gallate (1-).

According to the procedure of example 3, 2.3 g (4.43 mmol) of galliumtrifluoromethanesulfonate was employed in place of aluminumtrifluoromethanesulfonate to give 2.7 g of product as a solid (84%yield).

EXAMPLE 5

This example describes the preparation of tri-n-propyloxoniumtetrakis(trifluoromethanesulfonato)aluminate (1-).

To a well stirred solution of 6.3 g (13.2 mmol) aluminumtrifluoromethanesulfonate in 50 ml dry n-propyl ether in a Schlenk flaskunder dry argon was added 0.8 ml (10 mmol) epichlorohydrin. The mixturewas stirred at room temperature for 4 hr. The beige precipitate waswashed several times with n-propyl ether and dried in vacuo at 50° C.for 2 hr, 9.0 g (89% yield).

EXAMPLE 6

This example describes the preparation of tri-n-propyloxoniumtetrakis(trifluoromethanesulfonato)gallate (1-).

According to the procedure of example 5, 6.9 g (13.3 mmol) galliumtrifluoromethanesulfonate was used in place of aluminumtrifluoromethanesulfonate to give 9.2 g to product as a solid (85%yield).

EXAMPLE 7

This example describes the preparation of triethylsulfoniumtetrakis(trifluoromethanesulfonato)aluminate (1-).

To a well stirred slurry of 2.1 g (4.43 mmol) aluminumtrifluoromethanesulfonate in 20 ml dry diethyl sulfide in a Schlenkflask under dry argon and the mixture was refluxed for 6 hr. Thesupernatant diethyl sulfide was removed and the viscous lower phase waswashed several times with diethyl sulfide under reflux, and then driedin vacuo at 50° C. for 3 hr, 3.1 g (94% yield).

EXAMPLE 8

This example describes the preparation of diphenyliodoniumtetrakis(trifluoromethanesulfonato)borate (1-).

To a suspension of 2.1 g (4.89 mmol) diphenyliodoniumtrifluoromethanesulfonate in 20 ml 1,1,2-trichlorotrifluoroethane wasadded dropwise a solution of 2.2 g (4.8 mmol) borontrifluoromethanesulfonate in 1,1,2-trichlorotrifluoroethane™. Themixture was stirred under dry argon for 3 hr at room temperature.Diphenyliodonium tetrakis(trifluoro-methanesulfonato)borate wasprecipitated following dissolution of the precursor. The precipitate wastreated with a mixture of anhydrous sodium sulfate and sodiumbicarbonate in dry tetrahydrofuran. The tetrahydrofuran solution wasfiltered, concentrated under reduced pressure and precipitated usinghexane, filtered, and dried in vacuo, 4.1 g (95% yield).

EXAMPLE 9

This example describes and alternate preparation of diphenyliodoniumtetrakis(trifluoromethanesulfonato)borate (1-).

To a mixture of 1.5 g (4.8 mmol) diphenyliodonium chloride in 20 ml drynitromethane, was added an equimolar solution of silvertetrakis(trifluoromethanesulfonato)borate in nitromethane was added inone portion at room temperature. After stirring for 2 hrs theprecipitated silver chloride was filtered off and the filtrate was driedover anhydrous sodium sulfate-sodium bicarbonate as described in Ex. 8and then concentrated under reduced pressure. Hexane was added to causeprecipitation of the iodonium tetrakis(trifluoromethanesulfonato)borate,3.9 g (90% yield).

EXAMPLE 10

This example describes the preparation of acetyliumtetrakis(trifluoromethanesulfonato)borate(1-).

To a well stirred solution of 6.6 g (9.24 mmol) silvertetrakis(trifluoromethanesulfonate)borate in 20 ml liquid SO₂ at -40°C., was added 1.14 g (9.24 mmol) acetyl bromide. Silver bromideprecipitated immediately, and the mixture was stirred for an additional30 min. The solution was quickly filtered through glass wool in a cooledSchlenk flask (-30° C.), and the solvent was removed at this temperatureunder reduced pressure. Acetyliumtetrakis(trifluoromethylsulfonato)borate (1-) was obtained as anoff-white solid, 5.0 g (83% yield).

EXAMPLE 11

This example describes the preparation of 2,4,6-trimethylpyryliumtetrakis(trifluoromethanesulfonato)borate (1-).

A solution of 2.3 g (5.1 mmol) boron tris(trifluoromethanesulfonate) in1,1,2-trichlorotrifluoroethane was added dropwise to a well stirredsolution of 1.2 g (5.1 mmol) 2,4,6-trimethylpyryliumtrifluoromethanesulfonate (Org. Syn., 4, 1114) in 10 ml chloroform. Themixture was stirred for 30 min and hexane was added and the resultantprecipitate was removed by filtration, and dried in vacuo to give2,4,6-trimethylpyrylium tetrakis(trifluoromethylsulfonato)borate as anoff-white solid, 3.0 g (81% yield).

EXAMPLE 12

This example demonstrated the preparation of diphenyliodoniumtetrakis(trifluoromethanesulfonato)ferrate (1-).

Diphenyliodonium trifluoromethanesulfonate 2.65 g, (6.1 mmol) was addedto a suspension of 1.0 g (6.1 mmol) ferric chloride in 20 ml dry1,1,2-trichlorotrifluoroethane. The mixture was heated to reflux for 6hr to obtain diphenyliodoniumtrichloro(trifluoromethanesulfonato)ferrate as a solid. To said solid1.62 ml trifluoromethanesulfonic acid was added dropwise and thereaction mixture was further refluxed overnight. The beige solid formedwas dissolved in dry nitromethane containing 0.5 g anhydrous sodiumsulfate and sodium bicarbonate and the solution was filtered afterstirring. Removal of the solvent in vacuo diphenyliodoniumtetrakis(trifluoromethanesulfonato)ferrate (1-), 5.2 g (91% yield).

EXAMPLE 13

This example describes the preparation of triethyloxoniumhexakis(trifluoromethanesulfonato)stannate (1-).

To a suspension of 3 g (4.2 mmol) tetrakis(trifluoromethanesulfonato)tinin dry ethyl ether under argon was added 3 g (16.8 mmol) ethyl triflate.The mixture was refluxed for 14 hr. The precipitated oxonium slat waswashed several times with refluxing dry ether to remove excess ethyltrifluoromethanesulfonate. The resultant solid was dried at about 50° C.and triethyloxonium hexakis(trifluoromethanesulfonate)stannate (2-) wasobtained as a white solid, 3.8 g (80% yield).

The following examples demonstrate that the salts of the presentinvention are useful as initiators for cationic polymerization.

EXAMPLE 14

Polymerization of tetrahydrofuran: Tetrahydrofuran (89 g, 1.2 mol) wasdistilled from sodium-naphthalene into a dry 250 ml Schlenk flask underargon. Onium salt initiator was added directly from another Schlenkflask under argon with stirring. The solution was stirred for more than12 hrs at room temperature, at which time the gelled material wascompletely dissolved in a solution of water/tetrahydrofuran (1:20),using a mechanical stirrer. Addition of methanol precipitated aflocculent solid, which was filtered and dried in vacuo to givepolytetramethylene ether. Results are summarized in Table 1.

                  TABLE 1                                                         ______________________________________                                                         [Initiator]                                                                             Polymer-                                                            mol/      ization   %                                        Initiator        l × 10.sup.3                                                                      Time (hr) Yield                                    ______________________________________                                        (CH.sub.3 CH.sub.2).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Al.sup.-                           5.4       20        80                                       (CH.sub.3 CH.sub.2).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Ga.sup.-                           19.9      20        69                                       (CH.sub.3).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Al.sup.-                                    7.8       18        76                                       CH.sub.3 (C═O).sup.+ (CF.sub.3 SO.sub.3).sub.4 B.sup.-                                     8.1       16        67                                       C.sub.6 H.sub.5 (C═O).sup.+ (CF.sub.3 SO.sub.3).sub.4 B.sup.-                              6.7       16        64                                       ______________________________________                                    

EXAMPLE 15

Polymerization of cyclohexane oxide: into a dry 100 ml Schlenk flaskunder argon, and equipped with a magnetic stirbar, was placed 4 ml drycyclohexene oxide, 4 ml dry dichloromethane. Onium salt initiator (70mg) was added at -10° C. with stirring. The mixture was stirred 15 minat a temperature of -10° C., then quenched with aqueous ammoniumhydroxide. The polymer was precipitated with methanol and dried invacuo. Results are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                         [Initiator]                                                                             Polymer-                                                            mol/      ization   %                                        Initiator        l × 10.sup.3                                                                      Time (hr) Yield                                    ______________________________________                                        (CH.sub.3 CH.sub.2).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Al.sup.-                           12.8      0.25      98                                       (CH.sub.3 CH.sub.2).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Ga.sup.-                           12.0      0.5       91                                       CH.sub.3 (C═O).sup.+ (CF.sub.3 SO.sub.3).sub.4 B.sup.-                                     24.1      0.25      75                                       (CH.sub.3 CH.sub.2).sub.3 S.sup.+ (CF.sub.3 SO.sub.3).sub.4 Al.sup.-                           19.3      168       73                                       ______________________________________                                    

EXAMPLE 16

Polymerization of α-phthalaldehyde: a solution of 18.7 mgtriethyloxonium tetrakis(trifluoromethylsulfonato)aluminate in drynitromethane was added under argon to a 100 ml Schlenk flask containing25 ml dry methylene chloride, a magnetic stirbar, and 5.2 g ofα-phthalaldehyde cooled to -78° C. The reaction was allowed to continuefor 18 hr. Pre-cooled dry pyridine (10 ml) was added to the reaction at-78° C., and the reaction was poured into a mechanically stirredsolution of methanol. The precipitated polymer was filtered, washed withmethanol, and dried in vacuo, yield 98%. When the above polymerizationwas carried out using triethyloxoniumtetrakis(trifluoromethanesulfonato)gallate as initiator, the yield was69% in 4 hr.

EXAMPLE 17

Polymerization of β-propiolactone: A solution of 30 mg triethyloxoniumtetrakis(trifluoromethanesulfonato)aluminate in 1 ml dry nitromethanewas added to a 25 ml Schenk flask cooled to 0° C. under argon andcontaining 1 g β-propiolactone in 1 ml dry dichloromethane. The reactionwas allowed to stand for 18 hr at 0° C., then quenched with a few dropsof water. Solvent was removed under reduced pressure and the polymer wasprecipitated using hexane, filtered, and dried in vacuo, 95% yield. Whenthe above procedure was repeated withtetrakis(trifluoromethanesulfonato)gallate as the initiator, similarresults were obtained.

EXAMPLE 18

Polymerization of isobutyl vinyl ether: this monomer was polymerized indry hexane according to the method of example 17. The polymer wasterminated using aqueous ammonium hydroxide solution, precipitated frommethanol, filtered, and dried in vacuo. The results are summarized inTable 3.

                  TABLE 3                                                         ______________________________________                                                         [Initiator]                                                                   mol/     Temp.   Time %                                      Initiator        l × 10.sup.3                                                                     °C.                                                                            (hr) Yield                                  ______________________________________                                        (CH.sub.3 CH.sub.2).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Al.sup.-                           5.7      -78     0.5  96                                     (CH.sub.3 CH.sub.2).sub.3 O.sup.+ (CF.sub.3 SO.sub.3).sub.4 Ga.sup.-                           2.2      -78     0.5  92                                     CH.sub.3 (C═O).sup.+ (CF.sub.3 SO.sub.3).sub.4 B.sup.-                                     6.1      -78      0.25                                                                              91                                     ______________________________________                                    

EXAMPLE 19

Polymerization of 2-ethyloxazoline: freshly distilled 2-ethyloxazoline,15 g (0.15 mol), was placed in a dry 100 ml Schlenk flask and the systemwas evacuated. Dry argon was introduced followed by addition of 70 mgtriethyloxonium tetrakis(trifluoromethanesulfonato)aluminate under argonat room temperature. The argon in the flask was evacuated and the flaskand contents were allowed to stand for 10 days at which time acompletely gelled material was obtained. The reactions was terminatedwith water and the polymer was subsequently dissolved in acetonitrileand precipitated with ether. The precipitated polymer was isolated byfiltration and drying in vacuo, 82% yield. Polymerization with thecorresponding tetrakis(trifluoromethanesulfonato)gallate was similarlycarried out, 71% yield.

EXAMPLE 20

Polymerization of hexamethyltrisiloxane (hereinafter referred to as "D₃"): triethyloxonium tetrakis(trifluoromethanesulfonato)aluminate, 77 mg,was added to a solution of 5 g freshly sublimed D₃ in freshly distilledmethylene chloride (dried over P₂ O₅). The viscous material wasdissolved in hexane and polydimethylsiloxane was precipitated frompyridine, filtered, and dried in vacuo for 24 hr, 82% yield.

EXAMPLE 21

Polymerization of 1,3-dioxane: A jacketed tube equipped with a magneticstirrer and argon inlet tube was charged with 5.8 g (65 mmol) freshlydistilled 1,3-dioxane and 14 ml dry nitromethane. The system wasfreeze-thaw degassed and 80 mg triethyloxoniumtetrakis(trifluoromethanesulfonato)aluminate was added under argon at-15° C. and the reaction was allowed to continue for 15 hr. Thepolymerization was quenched by addition of a 5-fold excess (based oninitiator) of sodium ethoxide in methanol. The resulting polymer waspurified by dissolving it in tetrahydrofuran, precipitation withpetroleum ether, filtration, and drying in vacuo, 62 yield.Polymerization with triethyloxoniumtetrakis(trifluoromethanesulfonato)gallate was similarly carried out in37% yield.

EXAMPLE 22

Polymerization of 7-oxabicyclo[2.2.1]heptane (1,4-epoxycyclohexane): asolution of 5.6 g (57 mmol) freshly distilled 1,4-epoxycyclohexane in 16ml dry dichloromethane contained in a jacketed tube was cooled to 0° C.Triethyloxonium tetrakis(trifluoromethanesulfonato)aluminate, 100 mg,was added under argon. The reaction was allowed to continue at thistemperature for 5 days. The resulting polymer was isolated by filtrationand dried in vacuo, 73% yield. Polymerization with triethyloxoniumtetrakis(trifluoromethanesulfonato)gallate was similarly carried out in46% yield.

EXAMPLE 23

Preparation of pentakis(trifluoromethanesulfonato)niobium: 5.6 mltrifluoromethanesulfonic acid was added dropwise to 3.4 g (12.5 mmol)niobium pentachloride in 40 ml dry 1,1,2-trichlorotrifluoroethane™ underargon. The mixture was refluxed for 4 days. Removal of the solvent invacuo gave pentakis(trifluoromethanesulfonato)niobium as a white powder.

Preparation of triethyloxoniumhexakis(trifluoromethanesulfonato)niobate: 1.8 g (2.1 mmol)pentakis(trifluoromethanesulfonato)niobium, prepared above, was added to20 ml dry ether. Ethyl trifluoromethanesulfonate (1.1 g, 6.3 mmol) wasadded with stirring under dry argon. The mixture was slowly refluxed for10 hr. The solvent and unreacted ethyl trifluoromethanesulfonate wereremoved in vacuo to give triethyloxoniumhexakis(trifluoromethanesulfonato)niobate as a white solid, 87% yield.

The material obtained above was used to initiate polymerization oftetrahydrofuran according to the procedure of example 14 (9 gtetrahydrofuran, 82 mg triethyloxoniumhexakis(trifluoromethanesulfonato)niobate, 14 hr) to give 8.2 g ofpolytetramethylene ether, 68% isolated yield.

EXAMPLE 24

This example describes the preparation of triethyloxoniumhexakis(trifluoromethanesulfonato)tantalate.

Preparation of pentakis(trifluoromethanesulfonato)tantalum: 2.9 ml (33mmole) trifluoromethanesulfonic acid was added dropwise to 2.3 g (6.4mmol) tantalum pentachloride in 30 ml dry Freon™-113. The mixture wasrefluxed for 7 days. The solvent was removed in vacuo to givepentakis(trifluoromethanesulfonato)tantalum as an off white viscousresin.

Preparation of triethyloxoniumhexakis(trifluoromethanesulfonato)tantalate (1-): 0.6 g (3.3 mmol) ethyltrifluoromethanesulfonate was added to 2.1 g (2.2 mmol)pentakis(trifluoromethanesulfonato)tantalum, prepared above, in 25 mldry ether under argon. The mixture was slowly refluxed for 10 hr. Thelower phase which formed was washed several times with dry ether, anddried in vacuo to obtain triethyloxoniumhexakis(trifluoromethanesulfonato)tantalate (1-) in 83% yield.

This material was used to polymerize tetrahydrofuran according to theprocedure of example 14 (10 g tetrahydrofuran, 6.0 mg triethyloxoniumhexakis(trifluoromethanesulfonato)tantalate, 12 hr) to give 6.3 g ofpolytetramethylene ether, 63% yield.

EXAMPLE 25

This example describes the polymerization of cyclohexene oxide withdiphenyliodonium tetrakis(trifluoromethanesulfonato)ferrate (1-): asolution of 3 ml cyclohexene oxide in 3 ml dry dichloromethanecontaining 30 mg iodonium salt was subjected to irradiation with amedium pressure Hg lamp (Hanovia, 450 W, distance of 2 cm) for 15 min.The colored gelled material was cooled and diluted in tetrahydrofuran.Polycyclohexene oxide was precipitated by addition to methanol and driedin vacuo, 65% isolate yield.

The procedure was performed again in 3 ml acetonitrile as solvent (60min exposure) to give 36% isolated yield.

The procedure was performed again without solvent (15 min exposure) togive 82% isolated yield.

EXAMPLE 26

This example describes the preparation of triphenylsulfoniumtetrakis(trifluoromethanesulfonato)ferrate (1-): 1.4 g (8.7 mmol) ferricchloride was added to a suspension of 2.6 g (8.7 mmol)triphenylsulphonium chloride in 15 ml dry1,1,2-trichlorotrifluoroethane™. The mixture was refluxed for 1 hr togive a gray solid precipitate. Dropwise addition of 3.1 ml (34.8 mmol)trifluoromethanesulfonic acid was followed by heating the mixture toreflux for 6 hr. The solvent was removed under reduced pressure and 20ml dry nitromethane was added. The solution was dried (and residual acidremoved) over 0.5 g anhydrous sodium sulfate and 0.2 g sodiumbicarbonate. The supernatant liquid was filtered and the solvent removedunder reduced pressure to obtain triphenylsulfoniumtetrakis(trifluoromethanesulfonato)ferrate (1-) as an off-white solid,6.7 g (87% yield).

According to the procedure of example 25, 20 mg triphenylsulfoniumtetrakis(trifluoromethanesulfonato)ferrate (1-) and 4 ml cyclohexeneoxide were irradiated for 10 min to give polycyclohexene oxide, 3.2 g(83% yield).

EXAMPLE 27

This example demonstrates that oxonium salts of the present inventionpolymerize tetrahydrofuran result in high molecular weight polymers.

Tetrahydrofuran was bulk polymerized with triethyloxonium saltsaccording to the procedure described in example 14 to givepolytetramethylene ether. The results are shown in Table 4.

                  TABLE 4                                                         ______________________________________                                                        [Initiator]                                                                            Polytetramethylene                                                   mol      Ether                                                Initiator       l × 10.sup.-3                                                                    -- M.sub.w × 10.sup.-5                                                            -- M.sub.n × 10.sup.-5               ______________________________________                                        (C.sub.2 H.sub.5).sub.3 O.sup.+ Al(O.sub.3 SCF.sub.3).sub.4.sup.-.sbsp.-                      4.8      6.85      3.42                                       (C.sub.2 H.sub.5).sub.3 O.sup.+ Ta(O.sub.3 SCF.sub.3).sub.4.sup.-.sbsp.-                      5.3      6.35      2.77                                       ______________________________________                                    

EXAMPLE 28

This example provides a comparison of high molecular weightpolytetramethylene ether prepared using the onium salts of the presentinvention with those prepared according to corresponding prior artmethods. Tetrahydrofuran was polymerized according to the method ofRozenberg et al. Polym. Sci. USSR 1964, 6, 2246 and Yamashita et al. DieMakro. Chemie 1971, 142, 171. The results are presented in Table 5.

                                      TABLE 5                                     __________________________________________________________________________                 Polytetramethylene Ether                                         Oxonium Salt Solvent                                                                            Temp °C.                                                                    -- M.sub.w × 10.sup.-5                                                         -- M.sub.n × 10.sup.-5                    __________________________________________________________________________    (C.sub.2 H.sub.5).sub.3 O.sup.+ BF.sub.4.sup.-                                             ether                                                                              25   0.92   not measured                                    (C.sub.2 H.sub.5).sub.3 O.sup.+ Al(O.sub.3 SCF.sub.3).sub.4.sup.-                          ether                                                                              25   1.66   0.99                                            (C.sub.2 H.sub.5).sub.3 O.sup.+ Ga(O.sub.3 SCF.sub.3).sub.4.sup.-                          ether                                                                              25   2.82   1.48                                            (C.sub.2 H.sub.5).sub.3 O.sup.+ PF.sub.6.sup.-                                             CH.sub.2 Cl.sub.2                                                                   0   not measured                                                                         0.05                                            (C.sub.2 H.sub.5).sub.3 O.sup.+ Al(O.sub.3 SCF.sub.3).sub.4.sup.-                          CH.sub.2 Cl.sub.2                                                                   0   0.97   0.67                                            (C.sub.2 H.sub.5).sub.3 O.sup.+ Ga(O.sub.3 SCF.sub.3).sub.4.sup.-                          CH.sub.2 Cl.sub.2                                                                   0   1.14   0.75                                            __________________________________________________________________________

The above data indicate that the use of the inventive polymerizationinitiators produces polymers with greater molecular weights as comparedto non-inventive or conventional initiators, i.e., (C₂ H₅)₃ BF⁻ ₄ and(C₂ H₅)₃ O⁺ PF⁻ ₆.

EXAMPLE 29

This example illustrates that anions of the present invention, whichhave extended chain perfluorosulfonato groups on the metal of the anion,are also useful.

Preparation of tris(perfluorobutanesulfonato)aluminum: to a suspensionof 91 g Gramstad, T. J. Chem. Soc. 1956, 173) in 30 ml dry1,1,2-trichlorotrifluoroethane, 0.7 g (10.1 mmole) trimethylaluminum inhexane was added dropwise under dry argon. The mixture was refluxed for24 hrs. The product was vacuum filtered and washed several times withdry 1,1,2-trichlorotrifluoroethane and finally dried in vacuo to obtaintris(perfluorobutanesulfonato)aluminum as a white powder, 89 g (95%yield).

Preparation of tris(perfluorobutanesulfonato)aluminum: 3 g, (3.2 mol),prepared according to Haszeldine, R. N.; Gramstad, T. J. Chem. Soc.1956, 173), was suspended in dry ether and 3 equivalents ofepichlorohydrin were added under dry argon. The mixture was refluxed for24 hr. The precipitated solid was washed several times with dry etherand finally dried in vacuo to givetetrakis(perfluorobutanesulfonato)aluminate (1-) in 78% yield.

Tetrahydrofuran was bulk polymerized according to example 14 (20 gtetrahydrofuran, 200 mg tetradis(perfluorobutanesulfonato)aluminate(1-), 25 hr reaction), to give a 52% yield of polytetramethylene ether.

EXAMPLE 30

This example demonstrates the preparation of triethyloxoniumhexakis(trifluoromethanesulfonato)zirconate (2-).

Ethyl trifluoromethanesulfonate (1.2 g, 6.6 mmol) was added to asolution of 1.5 g (2.1 mmol)tetrakis(trifluoromethanesulfonato)zirconium prepared according to theprocedure of Schmeiber, M.; Sartaori, P.; Lippsmeier, B. Chem. Ber.1970, 103, 868, in 20 ml dry ether under argon. The mixture was slowlyrefluxed for 10 hr, and the precipitated solid was washed several timeswith dry ether and finally dried in vacuo at 40° C. for 2 hr to givetriethyloxonium hexakis(trifluoromethanesulfonato)zirconate (2-) in 89%yield.

This material was used to polymerize tetrahydrofuran and cyclohexeneoxide according to examples 14 and 15, respectively. In the case oftetrahydrofuran (10 g tetrahydrofuran, 67 mg triethyloxoniumhexakis(trifluoromethanesulfonato)zirconate (2-), 14 hr) a 58% yield wasobtained, while in the latter case (2 g cyclohexene oxide, 2 gdichloromethane, 2° C., 10 min), a 70% yield was obtained.

EXAMPLE 31

Acetylium hexakis(trifluoromethanesulfonato)niobate (1-) was preparedaccording to the procedure of example 10 in 88% yield. The salt thusprepared was used to polymerize tetrahydrofuran and cyclohexeneaccording to the procedure of examples 14 and 15 in 54% (12 hr, 25° C.)and 61% (15 min, 0° C.) yields, respectively.

As can be seen from these examples, the synthesis of all compoundswithin the scope of the invention can be performed by selecting theappropriate reagents and using the teachings of this specification andthe reference materials cited.

I claim:
 1. A process for the polymerization of a cationicallypolymerizable monomer comprising intimately contacting a cationicallypolymerizable monomer with a cationic polymerization initiator therebyinitiating polymerization of said monomer, said initiator beingrepresented by the following formula:

    Y.sub.a.sup.b+ [(RSO.sub.3).sub.n M)].sup.Z-

wherein: Y is a cation selected from the group consisting of oxonium,sulfonium, sulfoxonium, selenonium, iodonium, diazonium, pyrylium,carbenium, and acylium cations; R is independently selected from thegroup consisting of ##STR3## R₁ is hydrogen, halogen, an alkyl group oran aryl group; F is fluorine; M is an element chosen from Groups 3-15,inclusive, of the Periodic Table; z is 1, 2, 3, or 4; and a, b, and nare integers such that z is less than or equal to n and the product of amultiplied by b equals z.
 2. A process as recited in claim 1 whereinsaid monomer is one which is capable of being polymerized cationicallythrough initiation with an alkyl group or an aryl group containingcation.
 3. A process as recited in claim 1 wherein said monomer is oneselected from the group consisting of epoxides, oxetanes,tetrahydrofurans, tetrahydropyrans, vinyls, lactones, oxazolines,aziridines, cyclosiloxanes, ketals, cyclic anhydrides, lactams, andα-phthalaldehydes.
 4. A process as recited it claim 1 wherein thecontacting of said monomer and said initiator is carried out insolution.
 5. A process as recited it claim 1 wherein said polymerizationreaction is carried out under anhydrous conditions.
 6. A process asrecited it claim 1 wherein at least one alkyl group of aryl group isattached to the cation Y.
 7. A process as recited it claim 1 wherein Yis an oxonium cation.
 8. A process as recited it claim 1 wherein M is anelement selected from Groups 4-14, inclusive, of the Periodic Table. 9.A process as recited it claim 8 wherein M is an element selected from B,Al, Ga, Sn, Fe, Zr, Hf, Nb, and Ta.
 10. A process as recited it claim 1wherein each R individually represents a perfluorinated alkyl radical oraryl radical.
 11. A process as recited it claim 10 wherein R is each Ris individually a C₁ -C₁₀ perfluorinated alkyl radical.